1. Field of the Invention
This invention relates to early diagnosis of mastitis or garget by measuring the concentration of 3-hydroxybutyric acid (3-OHBA for short) in the milk of mammals.
2. Prior Art
The concentration of 3-OHBA in milk, which is less than 100 .mu.mol/l for normal cattle, is well known to increase drastically in the case of ketosis that is the dysbolism of lipid and carbohydrates. Reagents for taking an expeditious measurement of the concentration of 3-OHBA are now commercially sold by Sanwa Co., Ltd. ("Lactest") and other firms.
Various conditions have been studied by the inventors to uncover the association of all ketone bodies (acetone, acetoacetic acid and 3-OHBAs) in such body fluids as urine and blood with the quality of mammalian milk and the health condition of livestock, as already reported (see JP-A-62-135771 specification). It has been reported that ketosis conditions are induced not only by diabetes but by various forms of shock, organopathies such as hepatitis, infectious diseases and drug (e.g. salicylic acid) poisoning as well ("Clinical Diagnosis and Management by Laboratory Methods", 17th Ed., pp. 412-413, published by W. B. Saunders Co. (1984).
Reagents for the separation and quantitative determination of a ketone body recently developed by Sanwa Co., Ltd. and other firms are now being used not only for diagnosis of diabetes but also for measuring the degree of activity of cell mitochondria at the time of liver transplantation-determination of the degree of rejection after transplantation, or for other purposes.
However, never until now has there been any report about the association of ketosis with mastitis or garget; in other words, they have been considered to have nothing to do with each other. Nor has anything been reported about the association of a ketone body with mastitis or garget.
In general, early detection of mastitis during a period of human lactation is of vital significance in view of protecting infants and, at the same time, the mothers. Garget, which is a typical disease of dairy cattle that incurs serious economical losses, is a type of inflammation which attacks the mammary gland tissue and lactiferous duct mainly through bacterial infection, and inhibits the lactigenous function and exasperates permeation of the milk secreting cell membrane, thus producing unusual milk in which blood components are incorporated.
Dairy cattle produce a ketone body in the liver and digestive tracts after feed intake, which is then used as an energy source after oxidation in the heart, kidney, brain and other organs. In the mammae, however, the ketone body is used not only as an energy source but also for synthesis of short-chain fatty acids of milk components.
A cow with ketosis or having a high concentration of ketones in the blood is found to have decreases in the activity of peripheral lymphocytes and the number of T-lymphocytes, and this suggests that the cow has a great chance of suffering from garget due to a drop of immune responsibility.
In an initial stage of mastitis or garget, the affected mammary gland tissue (cells) is locally inflamed or broken on a small scale, and a part of the blood components is mixed with milk components in the lactiferous duct, aggregated lactiferous duct, lactiferous sinus and other regions, leading to the production of unusual milk.
Early diagnosis of mastitis or garget to measure to what extent the mammary cells are affected or broken involves measuring the content of chlorine in milk, counting somatic cells in milk, determining NAGase activity and the like. However, a problem with these procedures, which are all awkward to handle, is that they cannot be used for ordinary, expeditious detection.
In view of the above-mentioned problem, the present invention seeks to provide a process for early diagnosis of mastitis or garget, which makes it possible to easily learn whether or not the subject suffers from mastitis or garget during lactation or milking.
In order to achieve the above-mentioned object and with the fact that separation and quantitative determination of a ketone body can now be easily carried out in mind, the inventors have uncovered the correlation, so far not found, between 3-OHBA produced in milk and mastitis or garget. Thus, the inventors have accomplished this invention.